From c321387fd984d6082a3b5a1d603a18e51ed04212 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Tue, 19 Apr 2016 15:54:30 -0700
Subject: [PATCH 1/3] the installation of server unary interceptor

---
 server.go            | 12 +++++++++++-
 test/end2end_test.go | 29 ++++++++++++++++++++++++++++-
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/server.go b/server.go
index fde4311a..995dcaea 100644
--- a/server.go
+++ b/server.go
@@ -99,6 +99,7 @@ type options struct {
 	codec                Codec
 	cp                   Compressor
 	dc                   Decompressor
+	unaryInt	     UnaryServerInterceptor
 	maxConcurrentStreams uint32
 	useHandlerImpl       bool // use http.Handler-based server
 }
@@ -140,6 +141,15 @@ func Creds(c credentials.Credentials) ServerOption {
 	}
 }
 
+func UnaryInterceptor(i UnaryServerInterceptor) ServerOption {
+	return func(o *options) {
+		if o.unaryInt != nil {
+			panic("The unary server interceptor has been set.")
+		}
+		o.unaryInt = i
+	}
+}
+
 // NewServer creates a gRPC server which has no service registered and has not
 // started to accept requests yet.
 func NewServer(opt ...ServerOption) *Server {
@@ -494,7 +504,7 @@ func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.
 			}
 			return nil
 		}
-		reply, appErr := md.Handler(srv.server, stream.Context(), df, nil)
+		reply, appErr := md.Handler(srv.server, stream.Context(), df, s.opts.unaryInt)
 		if appErr != nil {
 			if err, ok := appErr.(rpcError); ok {
 				statusCode = err.code
diff --git a/test/end2end_test.go b/test/end2end_test.go
index 88f1dce2..73befc2f 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -420,6 +420,7 @@ type test struct {
 	userAgent         string
 	clientCompression bool
 	serverCompression bool
+	unaryInt          grpc.UnaryServerInterceptor
 
 	// srv and srvAddr are set once startServer is called.
 	srv     *grpc.Server
@@ -468,7 +469,9 @@ func (te *test) startServer() {
 			grpc.RPCDecompressor(grpc.NewGZIPDecompressor()),
 		)
 	}
-
+	if te.unaryInt != nil {
+		sopts = append(sopts, grpc.UnaryInterceptor(te.unaryInt))
+	}
 	la := "localhost:0"
 	switch e.network {
 	case "unix":
@@ -1685,6 +1688,30 @@ func testCompressOK(t *testing.T, e env) {
 	}
 }
 
+
+func TestUnaryServerInterceptor(t *testing.T) {
+	defer leakCheck(t)()
+	for _, e := range listTestEnv() {
+		testUnaryServerInterceptor(t, e)
+	}
+}
+
+func errInjector(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+	return nil, grpc.Errorf(codes.PermissionDenied, "")
+}
+
+func testUnaryServerInterceptor(t *testing.T, e env) {
+	te := newTest(t, e)
+	te.unaryInt = errInjector
+	te.startServer()
+	defer te.tearDown()
+
+	tc := testpb.NewTestServiceClient(te.clientConn())
+	if _, err := tc.EmptyCall(context.Background(), &testpb.Empty{}); grpc.Code(err) != codes.PermissionDenied {
+		t.Fatalf("TestService/EmptyCall(_, _) = _, %v, want _, error code %d", err, codes.PermissionDenied)
+	}
+}
+
 // funcServer implements methods of TestServiceServer using funcs,
 // similar to an http.HandlerFunc.
 // Any unimplemented method will crash. Tests implement the method(s)

From 310ca08496121aa6e62d33da072766f8e60bce44 Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Tue, 19 Apr 2016 15:56:17 -0700
Subject: [PATCH 2/3] gofmt -w

---
 server.go            | 2 +-
 test/end2end_test.go | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/server.go b/server.go
index 995dcaea..f7e674c7 100644
--- a/server.go
+++ b/server.go
@@ -99,7 +99,7 @@ type options struct {
 	codec                Codec
 	cp                   Compressor
 	dc                   Decompressor
-	unaryInt	     UnaryServerInterceptor
+	unaryInt             UnaryServerInterceptor
 	maxConcurrentStreams uint32
 	useHandlerImpl       bool // use http.Handler-based server
 }
diff --git a/test/end2end_test.go b/test/end2end_test.go
index 73befc2f..09b786d3 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -1688,7 +1688,6 @@ func testCompressOK(t *testing.T, e env) {
 	}
 }
 
-
 func TestUnaryServerInterceptor(t *testing.T) {
 	defer leakCheck(t)()
 	for _, e := range listTestEnv() {

From 616cb8ecfe14f14fc5e1d6cb3d9e89cb720b3a4a Mon Sep 17 00:00:00 2001
From: iamqizhao <toqizhao@gmail.com>
Date: Tue, 19 Apr 2016 16:25:23 -0700
Subject: [PATCH 3/3] Add the missing comment

---
 server.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/server.go b/server.go
index f7e674c7..53a2a92c 100644
--- a/server.go
+++ b/server.go
@@ -141,6 +141,9 @@ func Creds(c credentials.Credentials) ServerOption {
 	}
 }
 
+// UnaryInterceptor returns a ServerOption that sets the UnaryServerInterceptor for the
+// server. Only one interceptor can be installed. The construction of multiple interceptors
+// (e.g., chaining) can be implemented at the caller.
 func UnaryInterceptor(i UnaryServerInterceptor) ServerOption {
 	return func(o *options) {
 		if o.unaryInt != nil {